Indurated product and method of preparing same.



*UNITED STATES AgEN'r ()FFICE.

LEO BAEKELAND, 'OF YONKERS, YORK.

rnnoimrnn rnonoc'r AND METHOD or PREPARING SAME.

Specification of Letters Patent .Patent ed Dec. 7, 1909- No Drawing. Original application filed July 13, 1907, Serial Ho.- $3,684. minded and this application filed April 18, 1908. Serial No. 427,874.

To all whom it may cone-em:

Be it known that I, LEo H. BAEKELAND, a citizen of the United States, residing at Yonkers, in the county of Westchester and. State of New York, have invented certain new and useful Improvements in Indurated Products and Methods of Preparing the Same, of \which the following is a speci-.

In my prior application, Ser. No. 358,156,

- filed February 18-, 1907; I ahave described and claimed a method of in or cellular materials consistlng 1n impregnating or mixing them with a phenolic body and formaldehyde andv causing the same to react within the body of the material to yield an insoluble condensation of dehydration product. In the course of this reaction considerable quantities of water are promore complete control of the reaction is secured and other important advantages are attained as hereinafter set forth.

In practicing the process I may use commercial phenol, or cresobor its homologues or other phenolic bodies. LI may employ commercial. formaldehyde or solutions of anhydrous formaldehyde in phenol; or if desired" the polymer of formaldehyde, which on heating splits up into 'anhydrous forinaldehyde, may be used. Dehydrated mixtures of formaldehyde and a phenolic body. may be very simply prepared by adding to the 'water-containin mixture of commercial cresol and commercial (40%) formaldehyde a suflicient proportion of a solid Watersoluble salt capable'of absorbing or separating Water from the mixture. Under these conditions there are. formed immediately two distinct layers, the lower one being a' dense aqueous solution of the added salt, and the upper the dehydrated mixture. Such soluble salts as calcium chlorid and sodium *ch'lorid aresuitable for use in this manner.

, The dehydrated mixture may be used directly for impregnation and has the advantage of urating fibrous avoiding the introduction into the material of the considerable quantity of water present in commercial cresol andformaldehyde.

In most instances I prefer to heat the mixture of phenol or its homologues and formaldehyde, alone or in presence of catalytic or condensing agents, the formaldehyde being presentin about the molecular proporr; tion, that is to say about equal volumes of commercial cresylic acid and commercial formaldehyde. Under these conditions the bodies react upon each other and yield a product consistmg of two liquids whichsep: arate or stratify on standing. The lighter or supernatant liquid is an aqueous solution which contains the water resulting from the reaction or added with the reagents, whereas the heav er llqlild 1s oily or viscous 1ncharacter and contains the first productsof chemical condensation or dehydration, The liquids are readily separated or the water may be eliminated by evaporation. The oily liquid obtained as above described is found to be soluble in or miscible with alcohol, acetone, phenol and similar solvents or mixtures. of the same. This oily liquid'may be further submitted'to heat on a ivateror steam-bath in order to thicken it and to expel any water which it may can contain.

If the'reaction be permitted to proceed further the condensation product may acquire a more viscous character, becoming gelatinous or semi-plastic in consistence, or even solid at lower temperatures. This modification of the: product is fusible although insoluble or incompletely soluble in alcohol, but-soluble or partially soluble in acetone or a mixture ofacetone and alcohol. The condensation product having either the Ol1y or semiplastic character-may be subjected to further treatment as hereinafter described. This condensation product, or

the dehydrated mixture of a phenolic body and formaldehyde,jmay be mixed with or caused to impregnate wood or other fibrous or. cellular materials, andthis impregnation may be effected or facilitated by any of the 'well known methods, as for instance slight heating, vacuum impregnation, injection by force or under pressure, or the use of suitable solvents; or it may be a lied by simple soaking or immersion, or ioy brush or similar contrivancell means 'of a to convert the materials into a final product of condensation which is anmfus ble, hard material. of resinous appearance, insoluble in alcohol, acetone and other usual. solvents and little or not at all affected by most chemical reagents, as for instance'acids or alkalies. In order-to obtain this transformation into the final product heat is applied, a-nd the transformation may be facilitated by the addition of small proportions of catalytic or condensing agents. At temperatures below 100 C., the reaction is very slow and is often incomplete. At higher temperatures vapors of formaldehyde and the like may escape abundantly and thereby cause foaming and the production of bubbles, such escape involving moreover aloss of the reagent and disturbing the proportions between the coast ituents of the mixture or compound, all of which would prevent the formation of a prm'luct of maximum hardness and of uniform texture.

In order that I may avail myself of the advantage of higher temperatures I prefer to harden the composition or indurate the fibrous or cellular material in a closed vessel or mold under pressure, under-which conditions the operation proceeds with precision and a-uniform result may be attained.

According to circumstances, impregnation may be made as thorough as possible, or may be limited to the outer zone or outer layers of the wood in such manner as to produce' around the softer core or body a hard ened protective layer, which however extends deeper than a mere varnish or surface coating.

The methods as described for Wood can be 1 used for any fibrons or. cellular material whether of organic or morganic origin. In this manner pulp board or asbestos board or ,objects made of these or similar materials can be impregnated and hardened. Or the fibrous or cellular materials may be mixed in bulk With the dehydrated mixture or the initial condensation product thereof, and pressed or shaped as desired by the use of a suitable mold; or they may be prepared in the form of-a block or of a regular or irregular mass which may be cut, sawed, turned or otherwise manipulated to any desired form or size.

Whereas for organic materials such as woodit is desirable not to heat to a temperature above 110140 C.,'-in order to avoid injury to the fiber, .in the case of materials of norganic origin such as asbestos consid- 1 erably higher temperatures may be employed.

The word phenol as employed in the claims is intended to include the homologues of phenol or other phenolic bodies; and the word formaldehyde is intended" to include the polymers of formaldehyde.

This application is a division of my prior application, Serial No. 383,684, filed July 1:5, 1907.

I claim r 1. The method of indurating fibrous or cellular materials which consists in mixing formaldehyde and a phenolic body in proportions to yield an insoluble and'infusible reaction product,.separating water-from the i mixture, applying the resulting substantially water-free product to the fibrous or cellular material, and hardening the composition.

2. The method of indurating fibrous or cellular materials which consists in mixing formaldehyde and a phenolic body in proportions to yield an insoluble and infusible reaction product, separating water from the mixture, applying the, resulting substantially water-free product to the fibrous or cellular material, andhardening the composition by simultaneous application of heat and pressure.

3. The method ofindurating Wood which consists in mixing formaldehyde and a. phenolic body in proportion to yield an insoluble and infusible reaction product, separating Water from the mixture, applying the resulting substantially Water free product to the wood and hardening the composition.

4. The method of indurating wood which consists in mixing formaldehyde and a phenolic body in proportion to yield an insoluble and infusible reactionproduct, separating Water from the mixture, applying the resulting substantially water-free product to the. Wood and hardening the composition by simultaneous application of heat and pressure.

5. As a new composition of matter wood cell tissue impregnated with an infusible and insoluble condensation product of phenol and formaldehyde.

6. As a new composition of matter, a fibrous or cellular material impregnated with an infusibleand insoluble condensation product of phenol and formaldehyde.

In testimony whereof, I alffix my signature in presence of two Witnesses.

, LEO H. BAEK EIQAND. Witnesses M Am E. SGI-IOLDING,

Many L, SHORT. 

